SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c614755b5f6af71ea9c3e5e1f59c846f100bfa08e82f606b949f50ad525f70fb' 
  AND token = 'bXnCT5yIKpK/dM0q0qz5yTJvwFfR38TdFvZGiefaW2M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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