SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '584582fc83b4b591f2937f97f43abfc1a68bd806b630c5694dc96abd24d49891' 
  AND token = 'bnv/YfoPWYJLV5pbLNFqeb4fNH+SeMrUPBmHV01XHBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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