SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '763f3a3e7642a2a73898c8e7d673555d2f42eb49c1b667cecb481b90c23973e0' 
  AND token = 'Aq6s1PR2S1QfuzboVyiOk+fMsL8sIKCLPoSSHvQylfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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