SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e9c9051fa32c2c2d05a2c061ce52aacfdcae7bb234d5d16672c98b8cf89accf' 
  AND token = 'B3/QipwXGCGxaB5UUi1q/hEcA3RoBeLjwNTg9DzILuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}