SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a0daff921ad553b1e2bd4af1a2bb2dc0e5e200be087f02de92d01d256066bd55' 
  AND token = 'mtQcbxi4uLQGQujcw6bikJH7L1svz1dFww5ukHkVuzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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