SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '88c5f41cd0b6bb57198d974020ff82731745bd123fa3f2f341856f2862d66fb5' 
  AND token = 'zHYtwtO62J+25Nebsvgo+VMgHc/HvHqSNW2GKg+8hwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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