SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '216e13d3aaf0ccee2b3176cde7d07c5d2e35d8123d9e80a253a3cd100a1c51c9' 
  AND token = 'YjCPcl9lTzraLbAgP+ttm8sdTc0MUwpvEgsmpUCJP4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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