SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fa74019c151ba676d6f24f51be3b55f94fc3482dc5d431fa89678488cdcb89a' 
  AND token = 'rR9qdhVupyYckfeUJ727JX+YGQcwUbwrugSO75Cvmxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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