SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '57ba30e7afb6b8553fce375bf039f14d015ef9638b1bf720a124707919cfec91' 
  AND token = 'g64qhQbfFr7BVgA4p56hg1xxBkPpgiX73t3CBSA/LOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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