SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5b52c226a8d5293182d1b8cef3fd707326ea8d0b80ef180f86fedd64b2290f56' 
  AND token = 'bv00da2rUcyED8q3cRLns0857HV32WKj40+dHk9Ec40=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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