SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b356e479f5a3f13fda1afbd2534ddf852389fcab97509742210821a24c6d538' 
  AND token = '886OFPEeuVXCtCmh3Punmt6Flalxij3crNt5W6gO8lQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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