SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c1b5684119afbf1e7c938430a2e4a0133881f2e460dafe2a416813ec8ef35e03' 
  AND token = '1CkStOWqMBWc4I5H2Wl94J1G0Fcm8yC+JkX4G1/JwQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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