SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84041f5dcce3570993edeb00da23e0562743a2b794e23a2c9fdb6d285d09909b' 
  AND token = 'p1QWi2dAAQHsc4vHzOTX6ywjrQJiXJCSLN9BNUGUVV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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