SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cefdadaf6ac50592673371081f33c90b05ecf7e418afd386056ed0a9881f18d' 
  AND token = 'wFj7MMzZFVI+ANoherJ37g42RAXKNWlq1sZeCYJWCso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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