SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f3b82d5ade5b50a3b7a96775b273dc58c1e4b4c290a2dd3883c2037ead4657e' 
  AND token = 'lr53Fs2h6/KowOnWjrXjfsXqHabWTafDAW6/nO4YcP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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