SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c01c7121948966032e1e55a8ae7b39f4baa63aee429312b5a78a6a80c6b5733' 
  AND token = 'iZPMnk4vVp6+DrnWIO2KywsR8+HBSmxbDWRUSsedPiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}