SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '353d9cf46a0dbca8bd2f9c2a6b6cb7186515e4657bd9bb40839032fb69150145' 
  AND token = 'eOsiRhY7Q/FuMSFt6CwXfPqM5CicHqklMJiTOBhzLlI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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