SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '792153452805e8022655cfc44f451e27dc5e18d0d815ebe8726fd95267b06302' 
  AND token = 'ffz5xntvVMFTmuITTMwL9MmL3PHAL4irw2wHb+at7RQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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