SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bf6d07b9fcf1cfb1c5146a58b86eaad527e68549cb015f8923b0b3a1d7f3d2b' 
  AND token = 'l3wAtTeZ6/XIizr0B8scpwNL/5GjkqJ3U6zKZcRfwAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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