SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '706160f64bbae28e2d71c0826cadb1381aa190205cfd2baffa3be6adcfa36306' 
  AND token = 'nm+dEutYJbzr08ciKevhoyqMymnIFwbROkJ/0YXRUtI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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