SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54fd92edcf7606665e468ad44352f4abe872cb36c64dadbe033fa963200b4939' 
  AND token = 'pUlkFIao+/jd878+ouWSBZFOO+Z2A70X9aHmtYhR1gE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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