SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61139c8b6ff9395bb334d2635c1490c3853bcc13001a8d8710f7168539b87b27' 
  AND token = 'wR8svQ5TH0QkR2mtzTqJIgJXAJhY56dw2HtoHs4KFpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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