SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bffd2e29938b11de63dfb9793fcc55a795be66d4d4097527e8973e0a6336ccf3' 
  AND token = 'G/rUv+fvXQVhmqcGsg4f+WviNzGbEKiHaDr2l19vRqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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