SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aea064131ef5ab57b4c39a73dd23c1f535ca3bc95651085b4f02b78b68827d84' 
  AND token = 'L4AiMjs0zuUIYXpQEAQMt02IvWJ/k/52W1BnnS+DuFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}