SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e43a91eb7ab393b9f43b12c3f26fe050cda5af45511aad35848883b9a0cfcb3' 
  AND token = 'Tr8xvPUJksl4WV1mb8vhoHNi0NcGizwDyrhtF06W3A4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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