SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5beb19e02d6f649010deede5739a2fa15fac5f615660342c076e834ff5b3a69b' 
  AND token = '62qfjAFMQ1upBsybosTefeDRCW2W79csWxoPKKylZbc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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