SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '84ff51a51e196442dc99a947a22e18ce82dffc650c6177ef6683bf148de43021' 
  AND token = 'vtrwdQ31ql+n5VnuahJPlay9VMM2SEp8GPkwFzjOLyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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