SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '783c6226486f950effa13c3a6480d46a763fed79df28b7808a93ae8166251c60' 
  AND token = 'ZfOOtNdhGsgt1N2+OVGDBQBcfP2LDknaxH+Jhbet/m4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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