SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c3358b8b9b0dd380ee67222b24f26c1255a8d4ad08b220d133e97c32e45e39a' 
  AND token = 'rUcbvPsCQMJwNamY/HkXRJKN9Qp+VYLoZEO2uhdBwG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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