SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd89349ad9466a712f2abda10d14c1172b984c5818f36c5039a9297b17b8e2a0e' 
  AND token = '6QOQ+7Btg6ex/OL3vGs18+NHCaFfJ3WWSFCtzeTprqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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