SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9e596545e1aeb1132b71c963990dc38508c2d831e63bf614178cf7a5639b17d' 
  AND token = 'BMTPSmTPqV7pmV7hSyI2Lwx2KgtXzAl0ZhyQ6MjOndQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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