SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd6912193ba2a1ff5955350191ee13a262f6b5dd18417320b46b5be6d0afd1cc' 
  AND token = '+l783Z3iE3f3cTt9rvMSfzUxNOZGEWmMbfroNtgqG24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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