SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f80f30ef9260eee1a16c1ff7a768b21a6d64324d973992e852d237ed177615ee' 
  AND token = 'MJyLG6LDLomsucWQ/laO8PWu4BjQeHF5ogSegCfayUI=' 
  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"
    }
  }
}