SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8efbdabf16691b72e122cfb4cadf8201cee47523532040f6b1f898cddb92aad7' 
  AND token = 'Ca1oK3ZZci+nOtqIXRxcyKy1anILqnS58hPptck/TMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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