SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a06b2ab7c89e587212d126164a51b95cf21c4f058b00d899ec3df754d257007' 
  AND token = 'ZO2H0iG9YPWbCGXSOa45eD8DfqwDfqjowUwqkfhEiYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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