SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03da6e8945fe3f5227bca57d5499097b9de7a0d1aab6930eb5e83e5d10c65145' 
  AND token = '+JBpECVq2sAET1i4hC06whGxUa7zImaWYqiCFkpJaVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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