SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '230c3f615652a98580c1301bf5a701e9533d827bfb97523a68214ec99077a209' 
  AND token = 'HOcFPJ8SBbGIt/gb/ToPwJqJELUIX57/K+pBhEudUH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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