SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fb510f30d8f14ae6fa4218cb7634b82b15f95bc41078784193240a0edf5a83e' 
  AND token = 'RglZAI9PTvQlmYMbzb6YuH8JJlfyKoJ/z3q2ffjJj9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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