SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6f1b5f2d62e330b936e14e485a84d317d799687740accfc1f75846ff247ec14a' 
  AND token = 'K1n1FfFroT4zKgITLdB9bqNGsvdwECtw3iy69zMjA60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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