SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe1822b8853938591dd53a2f8b85d74b87d7f745c9680c6d9abf0dd83d5e3490' 
  AND token = '+1BqkmGq7r2CYW1q3xiu+ZN6hmNLLpCPYPaun1sWAqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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