SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2ffdfc525e438e1a7327622329cf89b45ec2413aa0e56126d793f6a3bea8cf9' 
  AND token = 'bTQzanwdq1uaC2OmQLJiXmjeGq3DV0FhulJPBo/XyAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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