SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fffa854e23cbff3f807193a9591f47d465d5dc0fae8f1c1c911eccc04bba8a2f' 
  AND token = 'ASUguylaoZqSve5Q0E85E1/Xzm5N6lT1iZua3gKdbgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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